If it's in a datsun 1200 then I'd suggest the borg warner diff, with 28 spline axles should cope with enough grunt to make sub 9 second 1/4 mile runs.

BUT - the big thing I love about the ford 9" is the centre is removable, so if you want to change ratios, or run one with a spool at the strip and one on the street with an lsd and different ratio or whatever - you can do it easy. the borgwarner, you have to set the gears up in the housing each time (or swap entire housings).

I still run bw diffs on the charger, since I've got a stockpile of housings, gearsets and lsd centres for them, but I ran ford 9" diffs on the last few toranas I had, and never thought twice about it.